A wide variety of equipment and systems, such as portable and desktop computers, mainframe computers, communication infrastructure frames, automotive equipment, etc., include heat-generating components in their casings. As increasingly dense and higher performance electronics are packaged into smaller housings, the need for effective cooling systems is paramount to prevent failure of such sensitive electronics devices. One method used to remove heat from such equipment is to have an axial fan draw air from the exterior, of the casing to blow cooling air over the heat-generating components. However, as the number of electronics devices in offices and households increases, so too does the number of cooling fans. As such, fan noise becomes significantly loud and undesirable.
Typically, known fan assemblies include a fan blade structure, fan housing and a discrete motor. The fan motor is centrally mounted to the housing and the fan blade assembly is attached to the shaft of the motor. These types of fan assemblies are susceptible to a variety of failures. For example, the reliability of the motor used in the fan assembly may be compromised due to the heat generated by the motor or the heat of the surroundings in which the motor operates. Similarly, the heat affecting the motor also may affect the life of the fan bearings, resulting in premature failure of the fan. Another disadvantage of existing fan assemblies is the noise generated by these devices. As the density of electronics devices increases and as increasing numbers of transistors are packed into CPU cores, increased cooling becomes paramount. Generally such increased cooling comes at cost in the form of increased noise. Fans may be required to be bigger, thereby requiring noisier higher torque motors. Or, higher rotational speeds may be required, resulting in noisier motors. Alternatively, multiple fans may be used, which also results in increased noise due to the multiple motors in operation.